A systematic review on new advancement and assessment of emerging polymeric cryogels for environmental sustainability and energy production

In this review article, main focus was on the macro-porous cryogels synthetic routes and their applications. Porosity of the material is the main factor of attention for different applications. Here, we highlighted the different feasible synthetic routes for cryogels synthesis which is the demand of the present era. In multiple research articles, redox initiation cryo-polymerization route was implemented for cryogels synthesis which is time consuming and expensive. To overcome this problems, other rapid and efficient synthetic routes like UVradiation and gamma-radiation were used which shown better results. Different factors were studied, that effects cryogels porosity as well as their applications. Spilling of oil from tankers as well as organic pollutants from industries entering into the seawater is the main problem of water pollution. To remove this pollutants, there is always a need to fabricate highly porous hydrophobic/hydrophilic materials. Hydrophobic cryogels were the main point of this review article for oil/water separation with better and rapid absorption efficiency in the range of 7-136 g/g. Similarly, pure hydrophilic cryogels and hybrid cryogels were also cast off for the removal and degradation/reduction purposes of dyes and nitro-compounds. The chitosan-based cryogels used for the dye adsorption with better and fast adsorption capacity was 1600 mg/g. The fabricated pure and hybrid cryogels were also cast off for the first time as a new tribo-positive material for the conversion of mechanical energy into electrical energy (triboelectric nanogenerators) for small electronic devices. In the last of this review paper, we were focused on the future challenges and difficulties as well as how to solved this challenges in near future. This review article will be the good contribution on macro-porous polymers for various application and will be highly useful for the readers and environmental researchers.